From 879bc2d27904354b98ca295b6168718e045c4aa2 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Mon, 19 Oct 2020 16:57:50 +0200 Subject: [PATCH] hil/parisc: Disable HIL driver when it gets stuck When starting a HP machine with HIL driver but without an HIL keyboard or HIL mouse attached, it may happen that data written to the HIL loop gets stuck (e.g. because the transaction queue is full). Usually one will then have to reboot the machine because all you see is and endless output of: Transaction add failed: transaction already queued? In the higher layers hp_sdc_enqueue_transaction() is called to queued up a HIL packet. This function returns an error code, and this patch adds the necessary checks for this return code and disables the HIL driver if further packets can't be sent. Tested on a HP 730 and a HP 715/64 machine. Signed-off-by: Helge Deller Cc: --- drivers/input/serio/hil_mlc.c | 21 ++++++++++++++++++--- drivers/input/serio/hp_sdc_mlc.c | 8 ++++---- include/linux/hil_mlc.h | 2 +- 3 files changed, 23 insertions(+), 8 deletions(-) diff --git a/drivers/input/serio/hil_mlc.c b/drivers/input/serio/hil_mlc.c index 65f4e9d62a67..d36e89d6fc54 100644 --- a/drivers/input/serio/hil_mlc.c +++ b/drivers/input/serio/hil_mlc.c @@ -74,7 +74,7 @@ EXPORT_SYMBOL(hil_mlc_unregister); static LIST_HEAD(hil_mlcs); static DEFINE_RWLOCK(hil_mlcs_lock); static struct timer_list hil_mlcs_kicker; -static int hil_mlcs_probe; +static int hil_mlcs_probe, hil_mlc_stop; static void hil_mlcs_process(unsigned long unused); static DECLARE_TASKLET_DISABLED_OLD(hil_mlcs_tasklet, hil_mlcs_process); @@ -702,9 +702,13 @@ static int hilse_donode(hil_mlc *mlc) if (!mlc->ostarted) { mlc->ostarted = 1; mlc->opacket = pack; - mlc->out(mlc); + rc = mlc->out(mlc); nextidx = HILSEN_DOZE; write_unlock_irqrestore(&mlc->lock, flags); + if (rc) { + hil_mlc_stop = 1; + return 1; + } break; } mlc->ostarted = 0; @@ -715,8 +719,13 @@ static int hilse_donode(hil_mlc *mlc) case HILSE_CTS: write_lock_irqsave(&mlc->lock, flags); - nextidx = mlc->cts(mlc) ? node->bad : node->good; + rc = mlc->cts(mlc); + nextidx = rc ? node->bad : node->good; write_unlock_irqrestore(&mlc->lock, flags); + if (rc) { + hil_mlc_stop = 1; + return 1; + } break; default: @@ -780,6 +789,12 @@ static void hil_mlcs_process(unsigned long unused) static void hil_mlcs_timer(struct timer_list *unused) { + if (hil_mlc_stop) { + /* could not send packet - stop immediately. */ + pr_warn(PREFIX "HIL seems stuck - Disabling HIL MLC.\n"); + return; + } + hil_mlcs_probe = 1; tasklet_schedule(&hil_mlcs_tasklet); /* Re-insert the periodic task. */ diff --git a/drivers/input/serio/hp_sdc_mlc.c b/drivers/input/serio/hp_sdc_mlc.c index 232d30c825bd..3e85e9039374 100644 --- a/drivers/input/serio/hp_sdc_mlc.c +++ b/drivers/input/serio/hp_sdc_mlc.c @@ -210,7 +210,7 @@ static int hp_sdc_mlc_cts(hil_mlc *mlc) priv->tseq[2] = 1; priv->tseq[3] = 0; priv->tseq[4] = 0; - __hp_sdc_enqueue_transaction(&priv->trans); + return __hp_sdc_enqueue_transaction(&priv->trans); busy: return 1; done: @@ -219,7 +219,7 @@ static int hp_sdc_mlc_cts(hil_mlc *mlc) return 0; } -static void hp_sdc_mlc_out(hil_mlc *mlc) +static int hp_sdc_mlc_out(hil_mlc *mlc) { struct hp_sdc_mlc_priv_s *priv; @@ -234,7 +234,7 @@ static void hp_sdc_mlc_out(hil_mlc *mlc) do_data: if (priv->emtestmode) { up(&mlc->osem); - return; + return 0; } /* Shouldn't be sending commands when loop may be busy */ BUG_ON(down_trylock(&mlc->csem)); @@ -296,7 +296,7 @@ static void hp_sdc_mlc_out(hil_mlc *mlc) BUG_ON(down_trylock(&mlc->csem)); } enqueue: - hp_sdc_enqueue_transaction(&priv->trans); + return hp_sdc_enqueue_transaction(&priv->trans); } static int __init hp_sdc_mlc_init(void) diff --git a/include/linux/hil_mlc.h b/include/linux/hil_mlc.h index 774f7d3b8f6a..369221fd5518 100644 --- a/include/linux/hil_mlc.h +++ b/include/linux/hil_mlc.h @@ -103,7 +103,7 @@ struct hilse_node { /* Methods for back-end drivers, e.g. hp_sdc_mlc */ typedef int (hil_mlc_cts) (hil_mlc *mlc); -typedef void (hil_mlc_out) (hil_mlc *mlc); +typedef int (hil_mlc_out) (hil_mlc *mlc); typedef int (hil_mlc_in) (hil_mlc *mlc, suseconds_t timeout); struct hil_mlc_devinfo {